1. Field of the Invention
The present invention generally relates to a swim fin. More particularly, the present invention relates to a retractable swim fin which increases swimming efficiency and which, when retracted, increases walking efficiency.
2. Description of the Prior Art
In accordance with the prior art a swim fin may be defined as an area expanding appendage which, when attached to a foot of a swimmer, enables the swimmer to generate more propulsive force through water. For optimum benefit, a swim fin generally has from 5 to 50 times the area of the swimmer's foot.
Various swim fin arrangements have been proposed and utilized to generally provide a more efficient swim fin. Representative of the prior art are the swim fin and swim shoe arrangements disclosed in U.S. Pat. Nos. 2,729,832 (Schmitz), 2,903,719 (Wozencraft), 2,980,926 (Wolshin), 3,082,442 (Cousteau), 3,171,142 (Auzols), 3,268,927 (Markowitz), 3,302,223 (Ciccotelli), 3,665,535 (Picken), 4,025,977 (Cronin), 4,209,866 (Loeffler), 4,250,584 (Korn), 4,657,515 (Ciccotelli), and 4,689,029 (Ciccotelli).
The patents issued to Schmitz, Auzols, Picken, Cronin, Loeffler, and Ciccotelli generally involve the angular orientation of a fin relative to the plane of a foot or the longitudinal axis of a lower leg of a swim fin user. While the patents issued to Wolshin and Markowitz generally involve footgear with a swim fin disposable either in a walking position or a swimming position. The patent issued to Cousteau generally involves a swim fin comprising a footgear section, a propelling section, and a interconnecting section having less rigidity than the footgear and propelling sections; whereas the patent issued to Korn generally involves a collapsable swim fin. And lastly, the patent issued to Wozencraft generally involves a forwardly projecting swim fin hingedly connected to a swim shoe so that the swim fin may be swung rearwardly of the swimmer's foot. Basically, most of the cited swim fin arrangements comprise a propelling section angularly oriented with respect to the plane of a foot or the longitudinal axis of a lower leg of a swim fin user and a footgear section integral with the propelling section.